The invention concerns an arrangement for depicting a linear optical marking on a surface, such as a periphery such as a wall surface of a room, comprising a radiation source emitting light or laser radiation, as well as a first lens arranged in the optical path having a first and a second surface penetrated by the radiation, of which one surface consists at least in part of curved sections with different radii in cross section, having in particular an at least partially parabolic or elliptical trace in cross section, and extends symmetrically with respect to the plane of symmetry of the first lens, along which the parallel radiation travels.
DE-A-102 17 108 discloses a laser irradiating apparatus which is used in the construction industry. In order to generate a line without interruption running across a wide angle, it is provided that a laser beam bundle passing through a collimator lens falls on a rod lens, which has a semitransparent surface on the light source side, in order to reflect a linear light beam in the direction of the light source. The non-reflected light passes thus through a completely transparent surface of the rod lens, which faces away from the light source, and is refracted in order to generate a linear light beam in a second direction, which is opposite from the first direction.
U.S. Pat. No. 6,502,319 provides several cylindrical lenses or mirrors, by means of which the light beam emitted by the light source is distributed to the required extent, in order to depict a line of visible light on a surface, which starts directly in front of a housing where the light source is accommodated.
Light beam leveling devices according to DE-U-203 04 117 and DE-U-203 04 114 have line lenses consisting of sections with different focal lengths in front of a light source, by which a linear light beam is to be generated.
DE-C-199 53 114 proposes the use of two lateral projection devices arranged side by side, each comprising a light source and an optical unit arranged in its beam path, for the purpose of generating two lines intersecting at a right angle on a workpiece under an optical marking system. In order to spread the light beam, U.S. Pat. No. 3,984,154 provides a lens which has the shape of a hollow cylinder section, on whose one edge surface a collimator laser beam impinges. The inner surface of the lens has a reflecting layer for the purpose of reflecting the light to a sufficient extent to the outside.
In JP-A-2004094123, a rod lens, whose outer surface is provided in sections with a reflecting layer, so that the impinging light is directly reflected, is utilized to generate linear markings. Light can pass through the lens in the areas in which a corresponding reflection layer is not provided.
A lens utilized according to U.S. Pat. No. 6,935,034 to spread a laser beam features a rectangular geometry with a rounded edge facing away from the light source for the purpose of achieving the desired spread of the light that passes through the lens.
A crossline laser is disclosed in EP-A-1 795 863. The lenses used have a first planar surface on which the laser impinges in order to then be refracted on the surface, which is elliptical in cross section and faces away from the beam, whereby an optical line is generated, which is projected as a marking on a surface. The intensity distribution along the line is not uniform. Rather, the intensity is greater in the central area of the line and decreases towards the outside.
A laser beam impinges on the flat rear side of a half-cylinder lens in order to linearly spread a laser beam according to U.S. Pat. No. 5,782,093.
A refractive-diffractive hybrid lens for forming a beam of high power diode lasers is known from DE-A-103 54 780. The lens is composed of a rectangular section and a cylindrical section, through which the light passes first.
An apparatus for depicting a linear optical marking according to DE-U-20 2004 007 476 features a channel-shaped lens, whose curved sections run along both sides of a plane which extends perpendicularly to the radiation impinging the lens.
According to DE-A-195 28 198, a laser beam impinges on a cylindrical lens in order to be linearly depicted by the latter on sensors, with which the intensity distribution of the laser beam is measured.